It is only reasonable to assume that we've only begun to see the types of interactions that will be occurring and the legal actions that will result.
Any proposed solution must not just work for yesterday and today, but work reasonably well into tomorrow. This characteristic is required for much the same reason as simplicity; as the interactions between the various legal domains occur, the guiding principles of the solution need to provide some measure of guidance. No matter how pretty a theory somebody may spin, any real-world legal solution will have its share of special cases and exceptions. The guiding principles themselves, as explained by the theory, must still provide guidance if they are to be of any use, even if society deliberately chooses to do something else. If the theory itself is contradictory on some issue or combination of issues before the real world is even considered, then the theory is of little use, and may even be a hindrance.
And not just tomorrow as in "next year", but hopefully for decades to come. Companies need to know that their business models will still be legal (or still be illegal) ten years from now with some level of confidence. The new technologies that are developed need to not affect the viability of the solution too much.
In order to accomplish this goal, it is clear that a solution tied too intimately to technology is doomed to fail this measure. Technologies are very ephemeral. This tells us that for better or for worse, we must create guiding principles that do not really relate to the intricate engineering details of what a technology is doing. We must take a higher level view of what is going on, and somehow manage to not get bogged down in details.
This will be a great challenge to correctly perform that balancing act, but if we can manage to find a solution that has long-term viability (a big if!), it also means that the precise details of the technology disputes of the future won't matter to the judge so much. Once the dispute's relationship to the guiding principles are ascertained, the technology will have to fade into near irrelevance. This is good news, because it means our judges and lawyers won't necessarily need degrees in engineering, just enough training to understand the principles of engineering (although even this lower standard is curiously absent in current lawyers).
It should be clear that the path we are currently on is the very antithesis of robustness. Once you start using technology to move content in a way not possible in the early 1980's, you are in trouble. There are simple issues on the Internet that remain largely unresolved, and are largely ignored because they provide the foundation of the Internet as we know it.
Another example of this, in addition to ones described elsewhere: Do you have the right to access content on public servers, or can I selectively deny certain corporations from accessing the information? For instance, do an Internet search for "eBay vs. Bidder's Edge"; eBay tried to deny Bidder's Edge access to their servers, which Bidder's Edge was using to download huge quantities of information to provide services to other people. This case "resolved" the issue only in the narrowest sense, and using the rather dangerous doctrine of trespass, which really doesn't make much sense in this context.